LEARNING TARGET: I will be able to use The Law of Conservation of Energy to solve motion problems that include energy gained/lost during today's class

WORDS O' THE DAY:

• Work: A transfer or change of Energy
• Gravitational Potential Energy: Energy based on altitude
• Kinetic Energy: Energy of motion based on mass & velocity
• Mechanical Energy = The sum of all potential and kinetic energy in a system
• friction = Heat energy is generated when a moving object transfers some of its energy to individual molecules (such as air)

CALENDAR:

Work, Power & Energy Test on FRIDAY, March 10th.

FORUMULAE OBJECTUS:

• U_g = mgh
• KE = 1/2mv²
• TME = U + KE
• W = Fd = Fdcosθ = ∆E
• ∆E = 0
• ∆KE + ∆Ug = 0 (when friction is absent)
• ∆E = +/- W (when energy is lost or gained)
• ∆KE + ∆Ug = +/- W (when energy is lost or gained)

WORK O' THE DAY:

Now let's return to our Physics Classroom problem set. Please work on a couple of the pink (friction) problems

Keep in mind that friction is f=μN = μmg

Please ignore Problem #15.

I've marked problems involving friction in PINK. If you keep in mind that friction is a force that can (and does) do work (Work = fd) on an object in motion AND that friction is f=μN = μmg, then you should be able to take a stab at the friction problems.

NOTES: HOPEFULLY you have done a bunch of these already

Problem #10 is fairly general

Problem #11 will have you think but nothing TOO strenuous

Problem #12 & 13 are fairly general

Ignore Problem #15

Problem 16 is a good, challenging problemm...but not TOO nasty

Problem #17 is fairly general

Problem #20 (requires friction which is fun) & 22 are fairly straightforward but the last parts will make you think a bit.

Problem #24 & 25 are fairly general

Problem #28 requires a CLOSE READING of the problem (requires friction which is fun)

Problem #31 is difficult and requires friction which is fun

Problem #32 is also fairly rigorous, but really kinda cool (friction here too)!